Dual compound carburetor intake manifold



July 19, 1955 F. c. BURRELL ET AL DUAL COMPOUND CARBURETOR INTAKE MANIFOLD Filed Jan. 16, 1953 ATTORNEYS July 19, 1955 F. c. BURRELL ET AL DUAL COMPOUND CARBURETOR INTAKE MANIFOLD 2 Sheets-Sheet 2 Filed Jan. 16, 1955 I l I 4 BY pafiii'igai l m ATTO RN EYS United States Patent C) D AL CED/WOUND CAREURETOR INTAKE MANE JLD Frank C. Bnrreli, Detroit, Edgar Haigh, Wyandotte, and Paul. F. Keydel, Detroit, iviiclL, assigno-rs to General lvlotors Corporation, Detroit, Nlicln, a corporation of Delaware Application January 16, 1%3, Serial No. 331,658

14 Claims. (Cl. 12352) The present invention relates to charge forming devices for engines and has particular relation to an intake manifold for use with a multiplicity of compound carburetors for supplying mixtures to cylinders for V-type or other internal combustion engines.

Numerous attempts have been made to improve the volumetric efiiciency of V-type engines by the use of multiple carburetion. However, due to the angular disposition of the cylinders and the space limitations in a V-type engine, it is difficult to provide an intake manifold having separate or independent distribution passages that are disposed so as to permit grouping of the cylinders so as to obtain the desired engine output. Although intake manifolds have been developed that allow the desired grouping of the cylinders, they are not well adapted for use with multiple carburetors. When multiple carburetors are placed on the intake manifolds employed heretofore, substantial variations occur in the resistance to the fiow of fuel mixtures into the individual cylinders. This results in a non-uniformity of fuel charges which is detrimental to obtaining optimum engine output. This problem is particularly acute where it is desired to employ a multiplicity of compound carburetors.

It is proposed to provide an intake manifold that is adapted to employ a multiplicity of compound carburetors whereby a substantailly uniform charge will be delivered to every cylinder. The manifold is provided with mounting means at each end for the compound carburetors. The mounting means are positioned so that during operating conditions requiring the use of all of the supply passages of the compound carburetors, the flow resistance for each individual cylinder will be approximately equal. It is also proposed to interconnect the passages of each group of cylinders so that more than one compound carburetor may be utilized for supplying each of the individual cylinders.

In the drawings:

Figure l is a plan view of an intake manifold embodying the present invention, parts thereof broken away to show the interior structure of the intake manifold.

Figure 2 is a side elevational view of an engine employing charge forming means embracing the principles of the invention.

Figure 3 is an end view of the manifold taken substantially along the plane of line 3-3 with parts thereof broken away to more clearly show the passages therein.

Figure 4 is a cross-sectional view of the manifold taken substantially along the plane of line 4-4 of Figure' 1.

Figure 5 is a side elevational view of the manifold taken substantially along the plane of line 5-5 of Figure 1.

Figure 6 is a fragmentary view of a compound carburetor, a portion being broken away to show the jets and throttle valves.

The engine employed in practicing the invention is a V-type, eight cylinder, internal combustion engine Patented July 19, 1955 especially applicable for the operation of motor vehicles. The engine 20 includes a block 22 having angularly disposed right and left banks 24 of cylinders which are provided with separate heads 26. The cylinders in each bank are provided with exhaust manifolds 28 adapted to discharge the exhaust gas from the engine 20 into the atmosphere through exhaust pipes 30. The exhaust pipes 30 are adapted to be cut off by a thermostatic heat control valve 32 which will open when the engine 24 is warm to permit the exhaust gases to escape through the exhaust pipes 30.

The engine 20 is provided with an inlet manifold 34 having outlet ports 36 adapted to be connected to inlet passages formed in the heads 26 and leading to the different cylinders of the engine 20. The manifold 34 is supplied with combustible mixtures for operating the engine 20 by a multiplicity of compound carburetors 38. The manifold 34 is preferably cast as an integral body having a pair of connecting passages 40 and 42 formed therein. The connecting passages 40 and 42 are approximately of equal length and cross-sectional area and they extend in substantially parallel relation to one another and with the banks 24 of cylinders of the engine 20. The first connecting passage 4:) is arranged directly above the second connecting passage 42.- The first connecting passage 40 has a set of branch passages 44 and 46 connected to one end 48 thereof which extend in opposite directions and are adapted to supply an end cylinder of the right bank and a middle cylinder of the left bank. The opposite end 49 of the same connecting passage 40 is also provided with a set of branch passages 50 and 52 for supplying the opposite end cylinder of the right bank and the remaining middle cylinder of the left bank. One end 54 of the second connecting passage 42 is also provided with a set of oppositely disposed branches 56 and 58 for supplying respectively, a middle cylinder of the right bank and an end cylinder of the left bank. The opposite end 60 of the second connecting passage 42 is similarly branched 62 and 64 for supplying the remaining middle cylinder of the right bank and the remaining end cylinder of the left bank. The branch passages are all of substantially equal length and cross-sectional area so as to provide substantially equal distribution of combustible mixtures to all of the cylinders of the engine 20. The ends of the branch passages form ports 36 in the side of the manifold 34. It will be apparent that the first connecting passage 40 and its associated branch passages 44, 46, 50 and 52 communicate with the two end cylinders of the right bank and the two middle cylinders of the left bank while the second connecting passage 42 and its associated branch passages 56, 58, 62 and 64 communicate with the two middle cylinders of the right bank and the two end cylinders of the left bank. The cylinders of the engine 20 therefore are divided into two different groups, one group being interconnected with the first connecting passage 40 and the other being interconnected with the second connecting passage 42. Since the first connecting passage 49 is located above the second connecting passage 42, it will be apparent that the branch passages extending from each end of the connecting passages 40 and 42 can cross over with respect to one another without unduly distorting any of the passages.

Each end of the manifold 34 is provided with a flange 66 having openings 63, 70, 72 and 74 therethrough. The diagonally opposite openings 63 and '74 and and 72 form sets of fuel supply passages 76, 78, 8t} and 82, which comprise primary 76 and 78 and secondary 80 and 82 passages that communicate with the separate sets of branch passages.

The primary 76 and 7S and secondary 3i and 82 passages of each set are disposed on opposite sides of retor 38 is fully open.

the ends 48, 49, 54 and 60 of the connecting passages 40 branch passages and ports. The primary passages 76 and 78 are approximately the same distance from the ports 36 at the ends of their associated passages as the secondary passages 80 and 82 are from the ports at the end of their associated branch passages. Therefore the average distance from each sets of primary and secondary passages to each of the associated ports is equal. Thus during conditions requiring the use of both passages there will be a substantially uniform flow resistance for each port. It should be noted that each cylinder may not only draw from the adjacent compound carburetor but also because of the connecting passages 40 and 42, they can also draw from a remote carburetor.

The primary and secondary passages are adapted to be supplied with combustible fuel mixtures by pairs of primary mixture supplying jets 86 and secondary mixture supplying jets 88 in the compound carburetors 38. The primary 76 and 78 and secondary 80 and 82 mixture supply passages terminate in the manifold 34 and originate in the compound carburetors 38 where the carburetor jets 86 and 88 form separate mixtures for each of the pairs of passages. The primary supply passages 76 and 78 are controlled by an automatic choke valve mechanisrn 90 which is adapted to restrict the passages anterior to the carburetor jets 86 for the purpose of supplying a richer mixture during the starting of the engine than at other times during engine operation. The carburetors 38 are also provided with the usual butterfly type throttle valves 91 for each of the-primary passages 76 and 78. The primary passages 76 and .78 maybe provided with throttle valves 91 secured to the same shaft 92 and operating as a unit for. controlling the supply of mixture through the primary supply passages. The secondary mixture supplying passages 80 and 82 may also be provided with butterfly throttle valves 94 on the shaft 96 and which likewise operate as a unit Within the carburetor for controlling the supply of secondary mixture to the branch passages. The carburetors 38 are provided with a throttle operating mechanism by which the throttle valves 91 for controlling the primary passages 76 and '78 are correlating with the throttle valves 94 for the secondary passages 80 and 82. The throttle valves 94 for the secondary passages 80 and 82 are held in closed position by means of a spring 98 until the throttle valves 91 for the primary passages 76 and 78 are open to the desired extent and until the choke valve 90 for the carbu- When the primarythrottles 91 are open to the proper point the lever 101 will engage the lost motion member 103 and open the secondary throttles 94. Thus the throttle control device operates the carburetors in such a Way that a combustible mixture will be supplied to the branch passages through the primary mixture supply passages 76 and 78 during all conditions of operation of the engine 20 and through the secondary mixture supply passages 80 and 82 only during certain conditions of operation of the engine 20. A compound carburetor of this type is disclosed in S. N. 257,578 filed Nov. 21, 1951 by Adolph F. Braun.

To assist in the starting of the cold engine 20 and to prevent the accumulation of condensed liquid gases in the connecting passages and 42, it is desirable to heat the connecting passages. fold 34 is formed in such a way as to provide a cross over heating passage 100. The passage has ports 102 and 104 formed at the opposite ends thereof which are.

adapted to communicate with exhaust passages formed in the heads 26 and leading from the middle cylinders of each bank. When the engine 20 is cold and the heat control valve 32 is closed, it willbe apparent that all of the exhaust from the cylinders in the right bank which normally would be discharged from the manifold 28 through the exhaust pipe 30 will be compelled to flow in a reverse direction. The exhaust from the end cylin- 4 ders of the left bank will flow into the exhaust manifold 28 then in a reverse direction through the exhaust passages for the two central cylinders of the bank and from which all of the exhaust gas from all of the cylinders of the left bank will be discharged through the exhaust passage leading to the port 102. From the port 102 the exhaust gases from all of the cylinders of the left bank will flow through the heating passage 100 from the port 102 and into a passage in the right bank leading to the two middle cylinders of the right bank. From the exhaust passage for the two middle cylinders of the right bank, the exhaust gas from the left bank will be discharged into the right exhaust manifold with the exhaust gas from the cylinders of the right bank. From the exhaust manifold all of the exhaust gas from the cylinders of both banks will be discharged from the engine 20 through the exhaust pipe. When the engine 20 is warm enough for normal operation and the heat control valve 32 opens, the exhaust gas from the cylinders of the right and left banks will follow the paths of least resistance which will be respectively through the right and left exhaust manifolds and right and left exhaust pipes. It will be apparent that under such conditions the flow of exhaust gas through the passage 100 in the intake manifold will be reduced to a minimum;

The heating passage 100 is formed transversely through the manifold 34 in such a way as to extend across To accomplish this the manithe walls 106 and 108 of the connecting passages 40 and 42 and to expose them to the heat in the exhaust gases that Will flow through the heating passage when the engine 20 is cold. The heating passage spreads out from each of the ports 102 and 104 in such a way as to provide a broader, more shallow passage where the heating passage extends beneath the connecting passages 40 and 42. The walls 106 and 108 of the connecting passages 40 and 42 are provided with a plurality of' parallel spaced fins 110 that extend parallel to the flow of the exhaust gases thereby increasing the amount of surface area exposed to the exhaust gases. This will produce a more eflicient heat transfer to the walls 106 and 108 of the connecting passages 40 and 42. Should any liquid fuels condense out of the combustible fuel mixtures and collect in the connecting passages 40 and 42, they will be immediately vaporized due to the, elevated temperatures of the connecting passages. As soon as the fuels are vaporized, they will be drawn into the branch'passages.

While but one embodiment of the present invention has been shown, it will be apparent to those skilled in the art that various changes and modifications may be made without departing from the invention. It is, therefore, to be understood that it is not intended to limit the invention to the singleembodiment disclosed herein, but only by the claims which follow.

What is claimed is:

1. An inlet manifold for engines comprising a body having independent manifold passage means, each of said passage means including a connecting passage formed in said body, each of said connecting passages having branch passages formed in said body and disposed in opposite directions from the opposite endsof said connecting passage, and separate primary and secondary mixture supply passage means formed in said body and intersecting each of said branch passages.

2. 'An inlet manifold for engines comprising a body having independent manifold passage means, each of said passage means including a connecting passage formed in said body, each of said connecting passages having branch passages formed in said body and disposed in opposite directions from the opposite ends of said connecting passages, separate primary and secondary mixture supply passage means formed in said body and intersecting each of said branch passages, and means for heating said inlet manifold.

having independent manifold passage means, each of said passage means including a connecting passage formed in said body, each end of said connecting passages having a pair of branch passages formed in said body and extending in opposite directions, and separate fuel mixture supply passage means formed in said body and intersecting each of said pairs of branch passages adjacent said connecting passage.

4. An inlet manifold for engines comprising a body having independent manifold passage means, each of said passage means including a connecting passage formed in said body, each end of said connecting passages having a pair of branch passages formed in said body and extending in opposite directions, and separate groups of primary and secondary supply passages formed in said body adjacent the opposite ends of said body, one primary and one secondary supply passage from the same group intersecting one of said branch passages.

5. An inlet manifold for engines comprising a body having independent manifold passage means, each of said passage means including a connecting passage formed in said body, each end of said connecting passages having a pair of branch passages formed in said body and extending in opposite directions, said branch passages having ends forming ports in the opposite sides of said body, and separate groups of primary and secondary supply passages formed in said body to intersect said pairs of branch passages to thereby supply a charge of combustible fuel mixtures to the ports associated with each of said pair of branch passages, the average distance from said primary and secondary supply passages to each of said ports directly supplied thereby being substantially equal.

6. An inlet manifold for engines comprising a body having independent manifold passage means, each of said passage means including a connecting passage formed in said body, each end of said connecting passages having a pair of branch passages formed in said body and extending in opposite directions, said branch passages having ends forming ports in the side of said body, separate groups of primary and secondary supply passages formed on the opposite ends of said body, said primary and secondary supply passages intersecting said branch passages to there by supply charges of combustible fuel mixtures to the ports associated with each of said pair of passages, the average distance from said primary and secondary supply passages to each of said ports directly supplied thereby being equal, and exhaust means for heating said inlet manifold.

7. An inlet manifold for an engine comprising a body, connecting passages positioned in said body in side by side relation, one of said connecting passages being disposed above the other, each of said connecting passages having branch passages formed in said body and extending in opposite directions from opposite ends of said connecting passage, said branch passages having ends form- I ing ports in the sides of said body, and carburetor supply duct means discharging directly into the oppositely extending branch passages adjacent each end of said connecting passage, the distance from each of said carburetor supply duct means to the ports directly supplied by said carburetor duct means being substantially equal.

8. An inlet manifold for an engine comprising a body, connecting passages positioned in said body in side by side relation, one of said connecting passages being disposed above the other, each of said connecting passages having branch passages formed in said body and extending in opposite directions from opposite ends of said connecting passage, said branch passages having ends forming ports in the sides of said body, compound carburetor supply duct means, one of said duct means communicating directly with the oppositely extending branch passages adjacent each end of said connecting passage, the distance from each of said compound carburetor supply duct means to the ports directly supplied by said duct means being substantially equal, and exhaust means for heating said inlet manifold.

9. An inlet manifold for an engine comprising a body, connecting passages positioned in said body in side by side relation, one of said connecting passages being disposed above the other, sets of oppositely extending branch passages formed in said body each end of said connecting passages having a set of branch passages joined thereto, said branch passages having ends forming ports in the sides of said body, sets of primary and secondary mixture supply passages intersecting the sets of oppositely extending branch passages, the primary supply passage of each set being disposed on the opposite sides of the junction between the connecting passage and the branch passages b from the secondary supply passage.

10. An inlet manifold for an engine comprising a body, connecting passages positioned in said body in side by side relation, one of said connecting passages being disposed above the other, sets of oppositely extending branch passages formed in said body each of said connecting passages having a set of branch passages joined thereto, said branch passages having ends forming ports in the sides of said body, sets of primary and secondary mixture supply passages intersecting the sets of oppositely extending branch passages, the primary and secondary mixture supply passage of each set being disposed on opposite sides of the junction between the connecting passage and the branch passages, the average distance from the primary and secondary mixture supply passages of each set of supply passages to the parts being directly supplied thereby being substantially equal.

11. An inlet manifold for an engine having angularly disposed banks of cylinders, said manifold comprising a member adapted to be disposed between said banks and having rows of outlets disposed on the opposite sides thereof, each of said rows including two end ports and two center ports adapted to communicate with said cylinders, two sets of branch passages each of which include a pair of branch passages, each of said branch passages extending transversely of said manifold and being disposed to interconnect an end port on one side of said manifold with a center port on the other side thereof, two independent connecting passages extending longitudinally of said member, the opposite ends of each connecting passage intersecting the center of a branch passage in each set, and separate mixture supply passages intersecting each of said branch passages.

12. An inlet manifold for an engine having angularly disposed banks of cylinders, said manifold comprising a member adapted to be disposed between said banks and having rows of outlets disposed on the opposite sides thereof, each of said rows including two end ports and two center ports adapted to communicate with said cylinders, two sets of branch passages each of which includes a pair of branch passages, each of said branch passages extending transversely of said manifold and being disposed to interconnect an end port on one side of said manifold with a center port on the other side thereof, two independent connecting passages extending longitudinally of said member, said connecting passages having substantially the same cross sectional area as said branch passages, the opposite ends of each connecting passage intersecting the center of a branch passage in each set, and separate primary and secondary supply passages intersecting each of said branch passages on opposite sides of the junction of the connecting passage and the branch passages.

13. An inlet manifold for an engine having a pair of angularly disposed banks of cylinders, said manifold comprising a member having rows of outlets disposed on the opposite sides thereof, each of said rows including two end ports and two center ports adapted to communicate with the cylinders in said engine, two pairs of branch passages extending substantially transversely through said member and being disposed adjacent the opposite ends of said end outlets on one side of said manifold and one of said center outlets on the opposite side thereof, a pair of connecting passages extending longitudinally of said member, the opposite ends of each connecting passage intersecting one of said branch passages substantially in the middle thereof, each of said connecting passages interconnecting a branch passage in one pair and a branch passage with the other pair, and a primary mixture supply passage and a separate secondary supply passage'intersecting each of said branch passages on opposite sides of the junction of the connecting passages with the branch passages, the average distance from said primary and said secondary supply passage to the ports directly supplied therefrom being substantially equal.

14. An intake manifold for an engine having angularly disposed banks of cylinders comprising a member adapted to be disposed between said banks, said member having a group ofsupply passages at each end thereof, each of said groups including a pair of substantially vertical primary supply passages and a pair of substantially vertical secondary supply passages, horizontal branch passages extending transversely through said member to form outlets in the opposite sides thereof for communicating with said cylinders in said engine, each of said branch passages, intersecting a primary and a secondary supply passage in one group, the average distance from the primary andsecondary mixture supply passages tolthe ports being directly supplied thereby being substantially equal, connecting passages extending longitudinally of said member, the ends of the connecting passage intersecting said branch passage between the junctions of said branch passage with said primary and secondary supply passages.

References Cited in the file of this patent UNITED STATES PATENTS Sullivan June 6, 1939 

